[TUHS] Whence 1st Edition Unix Kernel Assembly?

[lm@bitmover.com (Larry McVoy)]

On Thu, Apr 24, 2008 at 12:57:12PM -0600, M. Warner Losh wrote:
> In message: <4810D417.8040005 at bitsavers.org>
>             Al Kossow <aek at bitsavers.org> writes:
> : The critical point to add to this is that the data integrity needs to be
> : constantly verified, even on presumed stable storage, and it is migrated
> : to what at that time is easily to deal with storage, so you CAN easily
> : verify it.
> 
> I keep my archives on a series of disks.  There's always at least 2
> copies, often times more, and the underlying disks get swapped out on
> a round-robin basis.  Helps limit my exposure to one or two
> failures...  I've had horrible luck with all other methods...

We do the same thing here.  For /home which has all the stuff we really
care about we have 

	/nightly	- last night's copy of the data
	/nightly2	- same thing, night before
	/weekly		- last Sunday's copy of the data
	/weekly2	- same thing, week before

and we do it so that

	diff foo /nightly/$PWD

works.  Handy, that.
-- 
---
Larry McVoy                lm at bitmover.com           http://www.bitkeeper.com